Morphological aspects of rabbit masseter muscle after cervical sympathectomy

The objective of this paper was to study the effect of sympathetic innervation on morphological and histochemical aspects of skeletal muscle tissue. Rabbit masseter muscle was studied using histochemical and immunohistochemical methods for periods of up to 18 months post-sympathectomy. The morphological and enzymatic characteristics of control masseter muscles were similar on both the left and right sides. The main features were muscle fibres with a mosaic pattern and a predominance of type IIa fibres, followed by type I. Type IIb fibres showed very low frequency. Sympathectomized animals showed varying degrees of metabolic and morphological alterations, especially 18 months after sympathectomy. The first five groups showed a higher frequency of type I fibres, whilst the oldest group showed a higher frequency of type lib fibres. In the oldest group, a significant variation in fibre diameter was observed. Many fibres showed small diameter, atrophy, hypertrophy, splitting, and necrosis. Areas with fibrosis were observed. Thus cervical sympathectomy induced morphological alterations in the masseter muscles. These alterations were, in part, similar to both denervation and myopathy. These findings indicate that sympathetic innervation contributes to the maintenance of the morphological and metabolic features of masseter muscle fibres.

Greater auricular nerve neuropraxia with beach chair positioning during shoulder surgery

Neuropraxia of the greater auricular nerve is an uncommon complication of shoulder surgery, with the patient in the beach chair position. The greater auricular nerve, a superficial branch of the cervical plexus, is vulnerable to neuropraxia due to its superficial anatomical location. In this case series, we present three cases of neuropraxia associated with direct compression by a horseshoe headrest, used in routine positioning for uncomplicated shoulder surgery. We outline the risk of using devices of this nature and discourage the use of similar headrest devices due to the potential complications in headrest devices that exert pressure on the posterior auricular area to maintain head position during surgery.

Sex-related macrostructural organization of the deer's brachial plexus

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.

The cervical lymphatic system in newborn rats

In the present work the authors studied the morphology of the cervical lymphatic system using 26 new-born white rats of both sexes. The studies were performed by injecting China-ink under the skin of the angle of mouth and dorsal region of the auricle in order to visualize and then to proceed the dissection of lymph vessels and nodes under stereoscopic microscope. Morphological descriptions of superficial and deep lymph vessels and lymph nodes were made, recording: a dense capillary network of the superficial system that joins to larger branches going to the submaxillary lymph nodes, generally the only ones on each side; those lymph nodes send efferent branches to deep cervical lymph nodes generally also the only ones on each side; those lymph nodes give efferent branches which form the jugular lymphatic sac that joins the jugulo-subclavian junction; the jugular lymphatic sac may receive branches from the plexus, which accompany the omocervical and external jugular veins and branches coming from the thoracic limb, as well as may join the branches coming from the thorax and the branches in most of the cases form plexus branches and seldom appear by themselves.

Avaliação do bloqueio paravertebral cervical com ropivacaína em cães anestesiados pelo isofluorano e submetidos à osteossíntese radio-ulnar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da anestesia paravertebral cervical no bloqueio anestésico local do membro torácico em cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

RESULTS OF ULNAR NERVE NEUROTIZATION TO BICEPS BRACHII MUSCLE IN BRACHIAL PLEXUS INJURY

Objective: To evaluate the factors influencing the results of ulnar nerve neurotization at the motor branch of the brachii biceps muscle, aiming at the restoration of elbow flexion in patients with brachial plexus injury. Methods: 19 patients, with 18 men and 1 woman, mean age 28.7 years. Eight patients had injury to roots C5-C6 and 11, to roots C5-C6-C7. The average time interval between injury and surgery was 7.5 months. Four patients had cervical fractures associated with brachial plexus injury. The postoperative follow-up was 15.7 months. Results: Eight patients recovered elbow flexion strength MRC grade 4; two, MRC grade 3 and nine, MRC <3. There was no impairment of the previous ulnar nerve function. Conclusion: The surgical results of ulnar nerve neurotization at the motor branch of brachii biceps muscle are dependent on the interval between brachial plexus injury and surgical treatment, the presence of associated fractures of the cervical spine and occipital condyle, residual function of the C8-T1 roots after the injury and the involvement of the C7 root. Signs of reinnervation manifested up to 3 months after surgery showed better results in the long term. Level of Evidence: IV, Case Series.

Corneal sensitivity and slit scanning in vivo confocal microscopy of the subbasal nerve plexus of the normal central and peripheral human cornea

Purpose: To determine the subbasal nerve density and tortuosity at 5 corneal locations and to investigate whether these microstructural observations correlate with corneal sensitivity. Method: Sixty eyes of 60 normal human subjects were recruited into 1 of 3 age groups, group 1: aged ,35 years, group 2: aged 35–50 years, and group 3: aged .50 years. All eyes were examined using slit-lamp biomicroscopy, noncontact corneal esthesiometry, and slit scanning in vivo confocal microscopy. Results: The mean subbasal nerve density and the mean corneal sensitivity were greatest centrally (14,731 6 6056 mm/mm2 and 0.38 6 0.21 millibars, respectively) and lowest in the nasal mid periphery (7850 6 4947 mm/mm2 and 0.49 6 0.25 millibars, respectively). The mean subbasal nerve tortuosity coefficient was greatest in the temporal mid periphery (27.3 6 6.4) and lowest in the superior mid periphery (19.3 6 14.1). There was no significant difference in mean total subbasal nerve density between age groups. However, corneal sensation (P = 0.001) and subbasal nerve tortuosity (P = 0.004) demonstrated significant differences between age groups. Subbasal nerve density only showed significant correlations with corneal sensitivity threshold in the temporal cornea and with subbasal nerve tortuosity in the inferior and nasal cornea. However, these correlations were weak. Conclusions: This study quantitatively analyzes living human corneal nerve structure and an aspect of nerve function. There is no strong correlation between subbasal nerve density and corneal sensation. This study provides useful baseline data for the normal living human cornea at central and mid-peripheral locations